As the demand for new wireless communication services and systems continues to expand, appropriate unused frequency spectrum for these new wireless systems becomes more difficult to identify. Often the available spectrum is divided into different frequency bands for use by devices in a wireless system. In same cases, these frequency bands can be considered to define logical channels, i.e., at a given point in time and in a given geographical area, each frequency band is used by a group of wireless devices that communicate to each other.
Since the bandwidth efficiency of a communication system is limited by practical considerations, in some cases it may be desired to allow some of the wireless devices to use a wider bandwidth than originally allotted.
One technique that can be employed to enable wireless devices to use a wider bandwidth than is available in a predefined channel allocation is channel bonding. When channel bonding is used, two or more logical channels are linked together so that they may all be used together by one or more wireless devices to communicate data. These logical channels may or may not be adjacent in frequency and/or time. By bonding channels together, a greater total data throughput may be achieved than is possible with any one communication channel. Once a group of two or more communication channels have been bonded together, they may be treated by some layers of the communication protocol employed by a wireless device as if they constitute a single communication channel having a greater data capacity. Also, if one wireless device requires more bandwidth than a single communication channel provides, but does not need all of the bandwidth of the bonded channels, then the remaining unused capacity could be used by other wireless devices who are aware of the channel bonding and capable of operating with bonded channels themselves.
Some examples of when channel bonding may be used are: (1) where next generation wireless devices are being designed for an existing standard, and it is desired to guarantee coexistence, and/or interoperability with other, existing devices and services; (2) where two or more different types of wireless devices (e.g., narrowband and wideband) with different sets of capabilities and cost structures are envisioned to share spectral resources, and/or operate in the same system or network; and (3) where two or more different types of wireless devices (e.g., narrowband and wideband) are envisioned to be used in conformity with the same communication standard, due to different regulations in different regulatory domains.
However, when a system permits channel bonding, then certain problems may be presented, particularly for any reduced-capability devices that are not capable of such channel bonding. For example, in some wireless networks often a particular portion of the available communication resources (e.g., in time and/or in frequency) is allocated for transmission of control signals (e.g., beacons). These signals are used for coordination of communication resources (e.g., channels, bandwidth, time slots, etc.) among a group of devices that are sharing these resources. These signals are also used by “new” wireless devices to see if a channel is occupied or idle. Thus, when channel bonding is employed, it is essential that the control information is transmitted in a fashion that even the devices that are not capable of channel bonding are also able to receive this control information.
Accordingly, it would be desirable to provide a wireless communication device and method of wireless communication in a wireless communication system that support channel bonding and allow even those device that are not capable of channel bonding to share communication resources.
In one aspect of the invention, a method is provided for a wireless device to communicate in a wireless system. The method comprises: selecting a communication channel for communication; identifying a control channel that has been designated for communication of control information pertaining to the selected communication channel; listening for control information on the control channel to determine whether the selected communication channel is bonded with at least one other communication channel.
In another aspect of the invention, a wireless device is adapted to communicate in a communication system. The wireless device comprises: a receiver; a transmitter; and at least one antenna operatively connected to the receiver and transmitter. The wireless device: selects a communication channel for communication; identifies a control channel that has been designated for communication of control information pertaining to the selected communication channel; and listens for control information on the control channel to determine whether the selected communication channel is bonded with at least one other communication channel.
In yet another aspect of the invention, a method is provided for a wireless device to communicate in a wireless system. The method comprises: selecting a channel group for communication; identifying a control channel designated for communication of control information pertaining to the selected channel group; listening for control information on the control channel; and when no control information is received via the control channel, then transmitting control information via the control channel, the control information indicating that the control channel is bonded to at least one other communication channel.